For the following function, a$)$ give the coordinates of any critical points and classify each point as a re of any points of inflection; d$)$ identity intervals where the function is concave up or concave down, an

$h(x)=5x^3-15x$

a$)$ What are the coordinates of the relative extrema? Select the correct choice below and, if necessar

A$.$ The relative minimum point$($s$)$ is$/$are $$ and the relative maximum point$($s$)$ is$/$are $($Simplify your answers. Use integers or fractions for any numbers in the expression. Type an

B$.$ The relative minimum point$($s$)$ is$/$are $$ and there are no relative maximum point$($s$).($Simplify your answer. Use integers or fractions for any numbers in the expression. Type an

C$.$ The relative maximum point$($s$)$ is$/$are $$ and there are no relative minimum point$($s$).($Simplify your answer. Use integers or fractions for any numbers in the expression. Type and

$$ D$.$ There are no relative minimum points and there are no relative maximum points.